I did Psychology at AS Level last year. The teacher was really intense and I worked my butt off but I managed to receive an A at AS Level.
My general advice is to go over the content once it's been covered in class, not at the end when exams are imminent. I also made a revision timetable detailing specific days when I would be revising Psychology and when to do them. That way, I would revise without wasting my time.
I also did so many questions for revision. Because it was a new specification, there weren't many past papers available but the textbook I had provided many types of questions ranging from 3 marks to 12. Doing these tested my knowledge and I became harsh in my own marking as a means to improve.
I also attempted papers under timed conditions. One of the biggest issues in my exams is timing, and I still have this problem to this day, but doing past papers under timed conditions not only tests your knowledge but your time management. This really paid off because I finished both exams within the given time.
As for notes, it's mostly up to you, but I find making coloured notes and keeping a folder kept my organisation up to scratch. As for answering questions, I strictly kept to a PEEL structure (Point, Evidence, Explain, Link). With that structure, I was able to ensure that not only I was placing the correct content within the answer, but I was also answering the question at hand.
Hope that helps!